Protective device



Nov. 12, 1935. c. J. ANDERSON 2,020,818

. PROTECTIVE DEVICE Filed Jan. 11, 1933 2 Sheets-Sheet 1 Nov. 12, 1935.c J ANDERSON 2,020,818

PROTECTIVE DEVICE Filed Jan. 11, 1933 2 Sheets-Sheet 2 ijd fmsulafc'ora/6 Patented Nov. 12, 1935 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to protective devices, and more particularly tophase failure and phase reversal relays for use in polyphase alternatingcurrent circuits.

One object of the invention is to provide a compact, rugged andefiicient protective device of the aforesaid character consisting of asmall number of parts severally characterized by strength, simplicityand facility of assemblage.

Another object is to provide a protective device of the aforesaidcharacter having an improved electroresponsive operating unit includingmagnet frames so constructed and arranged as to provide enclosing andsupporting walls for the unit.

Another object is to provide an improved switch for devices of theaforesaid character and to also provide a rugged and reliable operatingmechanism for the switch including a small number of moving parts.

Various other objects and advantages of the invention will hereinafterappear.

The accompanying drawings illustrate an embodiment of the inventionwhich will now be described, it being understood that the embodimentillustrated is susceptible of modification without departing from thespirit and scope of the appended claims.

In the drawings,

Figures 1 and 2 are vertical and sectional views of a device embodyingthe invention;

Figs. 3 and 4 are top and front views, respectively, of the device shownin Fig. 1, the enclosing cover being shown in section;

Figs. 5 and 6 are perspective views of certain of the parts illustratedin Fig. 4, and

Figs. 7 and 8 are detail sectional views taken substantially on lines1'! and 8B, respectively, in Fig. 3.

The relay illustrated includes a pair of stationary contact devices Iand 2 and a cooperating movable contact element 3 under the control ofan electroresponsive device comprising a pivoted vane 4 having magnetframes 5 and 6 arranged on opposite sides thereof. As hereinafter setforth the magnet frames 5 and 6 are provided with energizing windingsfor connection across unlike phases of a polyphase alternating currentcircuit, and under normal conditions in said circuit vane 4 is held inthe position shown in Fig. 2 to maintain contact element 3 in engagementwith stationary contact devices I and 2, whereas under given abnormalconditions of said circuit said vane is moved by gravity into theposition shown in Fig. 1 to move said contact element out of engagementwith said stationary contacts.

More specifically, the vane 4 comprises a vertically arranged segmentaldisk of aluminum or other conductive but non-magnetic material pivotallymounted upon a horizontally arranged stationary pin 1 and the magnetframes 5 and 6 are 5 arranged in opposed relation with an air gaptherebetween for receiving said vane. As shown in Fig. 5, magnet frame 5is provided with a vertical side wall 8 having pole projections 9 and [0on the inner face thereof, and magnet frame 6 is 10 provided with avertical side wall I I having pole projections l2 and I3 on the innerface thereof. The pivot pin 1 is carried by an inwardly extending lug Mon the inner face of side wall 8 of magnet frame 5, and as shown in Fig.1 the pole projections 9, l0, I2 and [3 are arranged equidistant fromthe axis of the pivot pin 1 and in a staggered relation. As best shownin Fig. 5, each of the pole projections on magnet frames 5 and 6 has anenlarged disk l5 fixed to the inner end thereof by a screw 16, and apair of energizing windings I1 and i8 are mounted upon the poleprojections I0 and I2, respectively. As shown in Figs. 3 and 4, theouter faces of the side walls 8 and H of the magnet frames are providedwith projecting pads I9 and 20, respectively, which provide magneticpaths of low reluctance between the pole projections on the inner facesof said walls.

The side wall 8 of magnet frame 5 is provide-d with inwardly projectingmarginal portions forming a rear wall 2|, and a bottom wall 22 and theside wall II of magnet frame 6 is provided with similarly shapedinwardly projecting marginal portions forming a rear wall 23, and abottom wall 24. The magnet frames 5 and 6 are bolted together by a pairof non-magnetic studs 25 and 26, said studs being arranged withinopenings in the rear walls 2| and 23, and each having clamping nuts 21associated with opposite ends thereof. As shown in Figs. 2 and 4, eachof the studs 25 and 26 carries a non-magnetic spacing washer 28 which isarranged between the magnet frames 5 and 6 to maintain an air gapbetween the latter.

The operation of the aforedescribed electroresponsive device will now bemore fully described. Assuming that the windings l1 and I8 are connectedacross unlike phases of a polyphase alternating current supply circuitsubstantially independent alternating fiuxes will be produced in themagnet frames 5 and 6 which will be continuously displaced in phase.Such fluxes induce eddy currents in the vane 4 and the eddy currentsinduced by each magnet frame are acted upon by the flux produced in theother magnet frame to provide a torque which tends to rotate said vanein one direction or the other, dependent upon the phase relation of thecurrent in the windings H and |8. By properly connecting the windings I1and IS in a polyphase alternating current circuit a torque is producedwhich normally holds the vane 4 in the position shown in Fig. 2.

Upon failure of current in any phase of the supply circuit the torquefor holding the vane 4 in the position shown in Fig. 2 becomes zero,whereupon said vane automatically moves to the position shown in Fig. 1under the action of gravity. Also upon a predetermined general reductionof the line voltage such effective torque becomes so far reduced as tobe insufficient to hold the vane 4 in the position shown in Fig. 2,whereupon said vane also moves under the action of gravity to theposition shown in Fig. 1. Further, should the phase relation of thecurrent in the supply circuit become reversed from any cause eitheraccidental or voluntary the direction of torque on vane 4- will bereversed to drive said vane from the position shown in Fig. 2 into theposition shown in Fig. 1. Upon restoration of normal conditions in thesupply circuit following existence of any of the aforedescribed abnormalconditions the vane 4 is adapted to move automatically from the positionshown in Fig. 1 into the position shown in Fig. 2.

As is apparent, by arranging the magnet parts in the manner abovedescribed a very rigid and compact electroresponsive operating unit isobtained. Also it has been found that arrangement of the magnet frames 5and 5 in opposed relation upon opposite sides of the vane 4 andemployment of washers I5 to provide enlarged overlapping pole faces onsaid frames, tends to increase the efiiciency of the device. The abovedescribed electroresponsive operating device also has numerous otheradvantages, certain of which will be hereinafter discussed.

The stationary contact devices and 2 are mounted upon the upper edges ofthe magnet frames 5 and (3, respectively. Said contact devices aresimilarly constructed, each of the same being provided with a holder 30having a cylindrical carbon contact 3| slidably mounted within anopening therein. One of the contact devices is illustrated in section inFig. 8, and as shown therein holder 35 has a coil spring 32 associatedtherewith for biasing the contact 3| outwardly. Also as shown in Fig. 8,contact 3| is held in assembled relation within the opening in holder 30by a terminal pin 33 supported within an opening in said contact andprojecting into oppositely disposed openings in said holder. As shown inFigs. 1 and 3, each of the holders 3!! is provided with an upwardlyextending terminal portion 34 having a binding screw 35 associatedtherewith, and each of said holders is connected to the contact pin 33of its associated contact 3| by a flexible lead 35.

The contact devices and 2 are mounted upon the front ends of oppositelydisposed L-shaped insulating supports 31 and 38 which are fixed to theupper edges of the magnet frames 5 and 6, respectively, by screws 39. Asshown in Fig. 3, each of said insulating supports also carries a pair ofterminal devices 40. The contact holders 35 and the terminal devices 40are secured to their associated insulating supports by screws 4|, theheads of said screws being coimtersunk in the lower faces of saidsupports, as shown in Figs. '1 and 8. The heads of the screws 4| areinsulated from the magnet frames 5 and 6 by flat insulating strips 42interposed between said magnet frames and the lower faces of theinsulating supports 31 and 3B.

As shown in Fig. 3, insulating supports 31 and 38 are spaced to providea passage therebetween for receiving terminal wires associated with the5 energizing windings l1 and IS. The terminal wires for said windingsare not shown in the drawings, but as is apparent, such terminal wiresmay be passed upwardly through the space between supports 31 and 38 forconnection to the terminal devices 40. As shown in Fig. 8, each of theterminal devices 40 is provided with a pair of binding screws 43 and 44,one of said screws being provided for securement of a winding terminaland the other for securement of a line 1:! connection.

The movable contact element 3 includes a contact 45 for bridging thecontacts 3| of contact devices and 2. Bridging contact 45 is carried bya lever 46 which is operable as hereinafter set forth by a cam 41associated with vane 4 to move said bridging contact into and out ofengagement with the contacts 3|.

As shown in Figs. 4 and 6, lever 46 is provided with spaced side arms 48and 49 having hub portions 50 and 5| on the upper ends thereof which areconnected by an upwardly extending projection 52. Contact 45 is rivetedto an insulating plate 53 which is secured to the projection 52 of lever46 by screws 54. The hub portions 50 and 5| of lever 46 each have anoutwardly extending pin 56 fixed thereto, and said pins are journaledwithin openings provided in inwardly extending bearing projections 51and 56 on side walls 8 and II of the magnet frames 5 and 6. A roller 59for engaging the cam 41 is rotatably mounted upon a pin 60 which issupported within openings in lower ends of the arms 48 and 49 of lever46 and the hub portion 5| of said lever is provided with a downwardlyprojecting arm 6| which also cooperates with said cam.

Cam 41 is fixed to the right hand face of vane 4 by screws 63 and isrotatably mounted upon pivot pin 1 between the lug l4 on magnet frame 5,and a collar 64 fixed to said pin by a cotter pin 65. Cam 41 is providedwith a body portion 66 having a surface on the front edge thereof forengaging the roller 59, and said cam is also provided with a projectingbearing portion 61 having a rib 68 on one side thereof for engaging thearm 6| on lever 46. The front edge of said cam member is provided with anotch 69 for receiving roller 59 and the upper edge of said notch mergesat a point 10 with a convex cam surface 1|. Cam surface 1| is slightlyeccentric with respect to the axis of pivot pin 1 and the upper end ofsaid cam surface joins with a concave surface 12.

As hereinbefore stated, by properly connecting the coils l1 and I8 in apolyphase alternating current circuit vane 4 is normally subjected to atorque which is adapted to move the same out of the position shown inFig. 1 into the position shown in Fig. 2, and to maintain the same inthe latter position, whereas under given abnormal conditions in saidcircuit said vane is adapted to move under the action of gravity fromthe position shown in Fig. 2 into the position shown in Fig. 1.

As is apparent, with vane 4 positioned as shown in Fig. 2, the camsurface 1| engages roller 59 70 to maintain lever 46 in a positionwherein bridging contact 45 is held in engagement with the contacts 3|of the stationary contact devices. Also it should be noted that with theparts positioned as shown in Fig. 2 the concave surface 12 on the 1b cam41 engages roller 59 to prevent counterclockwise movement; of vane 4beyond the posi tion shown in Fig. 2.

Upon movement of the vane 4 out of the position shown in Fig. 2 into theposition shown in Fig. 1 the notch 69 in cam 41 moves into a positionfor receiving roller 59 and during final movement of the vane into theposition shown in Fig. 1 the rib 68 on said cam engages arm 6| on lever46 to positively move said lever into the position shown in Fig. 1.Bridging contact 45 is then maintained out of engagement with contacts3| and vane 4 is held against clockwise movement beyond the positionshown by engagement of roller 59 with the bottom of notch 69.

As is apparent, upon return of vane 4 from the position shown in Fig. 1into the position shown in Fig. 2, lever 46 is rotated in a clockwisedirection to return bridging contact 45 into engagement with thecontacts 3 I. However, it should be noted that upon initial movement ofthe vane 4 out of the position shown in Fig. 1 rib 68 on the cam memberdisengages the arm 6| on lever 46 and simultaneously the point Ill onsaid cam member engages the roller 59 to effect quick movement of saidlever 46 into a position wherein bridging contact 45 engages thecontacts 3|. Upon continued movement of vane 4 towards the positionshown in Fig. 2 the cam surface H, which as hereinbefore stated isslightly eccentric with respect to the axis of pivot pin 1, serves toeffect a slight continued clockwise movement of lever 46 to insure firmengagement of bridging contact 45 with the contacts 3| under the actionof the contact springs 32.

The device is provided with an inverted L- shaped cover 15 havinginwardly extending side walls for engaging the front and top edges ofthe magnet frames and 6. Said cover is constructed of non-magneticmaterial and is secured to the magnet frames by screws 16 which passthrough openings in said cover into tapped openings in lugs 11 on theside walls of said frames. As shown in Fig. 1 the cover has an opening18 at the rear thereof to facilitate wiring of the device, and as shownin Fig. 2 the rear wall of magnet frame 5 is provided with tapped boltreceiving openings 19 for securement of the device to a suitablesupport.

In connection with the foregoing it should be noted that the side wallsof the magnet frames 5 and 6 and the cover 15 serve to enclose thevarious parts of the device and protect the same against injury, and toalso prevent the accumulation of foreign matter within the device.Removal of the cover 15 obviously renders the parts of the switchmechanism accessible for inspection or repair. Also it should be notedthat with magnet frame 5 mounted upon a support, magnet frame 8 can bereadily detached therefrom for inspection or repair of the variousparts.

What I claim as new and desire to secure by Letters Patent is:

1. An alternating current relay comprising a movable circuit controllingelement and an electroresponsive operating unit therefor including apivoted vane operatively connected to said circuit controlling element,and a pair of stationary field elements arranged on opposite sides ofsaid vane, each of said field elements including a magnet frame having aside wall provided with a plurality of pole projections terminating inpole faces facing said vane, said pole faces being arranged in astaggered relation and the side walls of said magnet frames forming anenclosure for said vane.

2. An alternating current relay comprising a movable circuit controllingelement and an electroresponsive operating unit therefor including apivoted vane operatively connected to said element and a pair ofstationary field elements arranged on opposite sides of said vane, eachof said field elements including a magnet frame having a side wallprovided with integral pole extensions projecting towards said vane,said circuit controlling element and said vane being mounted upon theside walls of said magnet frames and said side walls forming anenclosure for said vane.

3. An alternating current relay comprising a movable circuit controllingmember and an electroresponsive operating unit therefor including a pairof spaced field elements and a vane movable in the space between saidfield elements and operatively connected to said circuit controllingmember, each of said field elements including a magnet frame having apair of projections thereon terminating in pole faces facing said vane,the pole projections on said field elements being arranged in astaggered relation.

4. An alternating current relay comprising a pair of magnet frames,non-magnetic means for securing said frames together with an air gaptherebetween, a rotatable vane arranged within the air gap between saidmagnet frames and a switch mechanism including a pivoted contact elementoperatively connected to said vane, said vane and said switch mechanismbeing mounted upon said magnet frames.

5. An alternating current relay comprising a pair of magnet frames,non-magnetic means for securing said magnet frames together with an airgap therebetween, a vane rotatably mounted upon one of said magnetframes and arranged within the air gap between said magnet frames, and aswitch mechanism mounted upon said magnet frames, said switch mechanismincluding an insulated stationary contact mounted upon each of saidmagnet frames and a cooperating bridging contact element rotatablymounted upon said magnet frames and operable by said vane.

6. An alternating current relay including a pivoted circuit controllingelement, an electroresponsive operating unit therefor having a pivotedvane operatively connected to said element, and a pair of field elementsarranged in opposed relation on opposite sides of said vane, each ofsaid field elements including a magnet frame having a side wall providedwith spaced pole projections terminating in enlarged pole faces facingsaid vane, said pole faces being arranged in a staggered relation andconcentric with respect to the pivot of said vane, and a magnet windingmounted upon one of the pole projections of each of said magnet frames.

'7. In an alternating current relay, the combination with a field unitincluding vertically arranged spaced magnet members having energizingwindings mounted thereon to be supplied with alternating currents ofdifferent phase relation, of a pivoted vane arranged to swing in avertical plane in the space between said magnet members, a pivotedcontact element having a given range of movement and a cam associatedwith said vane for moving said contact element in one direction througha major part of its range upon initial movement of said vane out of agiven extreme position and for moving said contact element through theremainder of its range upon continued movement of said vane into anopposite extreme position.

8. In an alternating current relay, the combination with a field unitincluding vertically arranged spaced magnet members having energizingwindings mounted thereon to be supplied with alternating currents ofdifierent phase relation, of a pivoted vane arranged to swing in avertical plane in the space between said magnet members, a pivotedcontact element movable in opposite directions between given extremepositions, a cam associated with said vane for moving said contactelement out of one extreme position and through a major part of itsrange upon initial movement of said vane out of a given extreme positionand for moving said contact element into its other extreme position uponcontinued movement of said vane into an opposite extreme position, and apart associated with said vane for engaging said contact element topositively move the same into its first mentioned extreme position uponreturn movement of said vane into its first mentioned extreme position.

9. In an alternating current relay, the combination with a switchmechanism including a movable contact element, of an electroresponsiveoperating unit therefor having a pivoted vane 0peratively connected tosaid element and a pair of field elements arranged in opposed relationon opposite sides of said vane, each of said field elements including amagnet frame having a side wall provided with a plurality of poleprojections erminating in pole faces facing said vane, said switchmechanism and said vane being mounted upon the side walls of said magnetframes, and non-magnetic means for securing said magnet frames togetherand for holding the same in spaced relation.

10. In an alternating current relay, the combination with a switchmechanism including a pivoted contact element, of an electroresponsiveoperating unit therefor having a pivoted vane operatively connected, tosaid element and a pair of field elements arranged in opposed relationon opposite sides of said vane, each of said field elements including amagnet frame having a side wall provided with a plurality of poleprojections terminating in pole faces facing said vane, said mechanismand said vane being mounted upon the side walls of said magnet frames,non-magnetic means for securing said magnet frames together and forholding the same in spaced relation and a non-magnetic enclosing coverfor said switch mechanism and said vane extending between said magnetframes and secured to the side walls thereof.

11. In an alternating current relay, the combination with a field unitincluding vertically arranged spaced magnet members having energizingwindings mounted thereon to be supplied with alternating currents ofdifferent phase relation, of a pivoted vane arranged to swing in avertical plane in the space between said magnet members, said vane beingbiased towards a given extreme position and being movable under theaction of said unit into an opposite extreme position, a movable contactelement biased towards open position, and a cam associated with saidvane for operating said contact element, said cam providing for movementof said contact element into closed position upon initial movement ofsaid vane out of its first mentioned extreme position and alsopermitting continued movement of said vane into its last mentionedextreme position while maintaining said contact element in closedposition.

CARL J. ANDERSON.

